External Fields, Density Functionals, and the Gibbs Inequality

By combining the upper and lower bounds to the free energy as given by the Gibbs inequality for two systems with the same intermolecular interactions but with external fields differing from each other only in a finite region of space , we show that the corresponding equilibrium densities must also differ from each other somewhere in . We note that the basic equations of density functional theory arise naturally from a simple rearrangement and reinterpretation of the terms in the upper bound Gibbs inequality for such systems and briefly discuss some of the complications that occur when the intermolecular interactions of the two systems also differ.     

Millimeterwave spectroscopy of transient molecules produced in a DC discharge

The construction of a millimeterwave spectrometer to study the pure rotational spectra of transient molecules in the gas phase is presented. The spectrometer is a source-modulated system combined with a free space glass discharge cell. Millimeterwave radiation has been produced using a frequency multiplier, the fundamental radiation source being klystrons. The spectrometer has been used to study the millimeterwave spectrum of carbon monosulfide (CS) and fluorine cyanide (FCN) produced inside the cell in a low pressure DC discharge of precursor gases. The quadrupole hyperfine structures of³³S and¹⁴N nucleus of CS and FCN have been resolved, measured and analysed.     

Radiative lifetimes in Ce I and Ce II

New radiative lifetime measurements based on time-resolved laser-induced fluorescence techniques are reported for 18 even-parity levels belonging to the 4f5d^26p and 4f ²5d ² configurations of Ce I and 6 even-parity levels belonging to the 5d^26s, 4f5d6p, and 4f6s6p configurations of Ce II. Free neutral and singly ionized cerium atoms were produced by laser ablation. The Ce I and Ce II levels range in energy from 26 545 to 29 102 cm^-1, and 42 573 to 48 152 cm^-1, respectively. Received 25 September 2002 Published online 4 March 2003     

Instrumental Requirements for Non-Invasive Blood Glucose Measurement Using NIR Spectroscopy

The magnitude of spectral change in blood glucose measurements with diffuse reflectance spectroscopy is investigated. Spectral change is estimated by simulation of light propagation in skin tissue and measurements of absorbance spectra of aqueous glucose solution. Required sensitivity of spectrophotometers for monitoring change in the blood glucose concentration as small as 10 mg/dL has been obtained using the estimated change in the absorbance spectrum and mean pathlength of light in tissue.     

Spectroscopic Determination of Oxygen DC Glow-Discharge Temperature: Radial Profile of Gas Temperature

Rotational temperature in the oxygen DC glow discharge is determined from atmospheric A-band of molecular oxygen. Two methods of estimation of this parameter taking into account the quality of the detected spectra are analysed and compared. Radial profile of the rotational temperature is measured. No radial variations of rotational temperature have been observed in the positive column under our experimental conditions.     

Fourier transform profilometry based on composite structured light pattern

In Fourier transform profilometry (FTP), the zero frequency of the imaged patterns will influence the measurement range and precision. The π phase shifting technique is usually used to eliminate the zero order component, but this method requires the capture of two fringe patterns with a π phase difference between them, which will impede the real time application of the method. In this paper, a novel method is proposed, in which a composite structured light pattern is projected onto the object. The composite structured light pattern is formed by modulating two separate fringe patterns with a π phase difference along the orthogonal direction of the two distinct carrier frequencies. This method can eliminate the zero frequency by using only one fringe pattern. Experiments show that there is no decrease in the precision of this novel method compared with the traditional π phase shifting technique.     

便携式近红外漫反射中药质量监控仪的研制

介绍了便携式近红外漫反射中药质量监控仪的设计思想、基本结构、测试条件和使用方法。该光谱仪具有体积小、重量轻、成本低等特点,现场监控中药质量是非常便利的。     

Analysis on Shack–Hartmann wave-front sensor with Fourier optics

In Shack–Hartmann wavefront sensor (SHWS), the behavior of the irradiance pattern produced by the micro-lens array is important for an accurate centroid estimation. In this paper, the behavior of a micro-lens array in SHWS is analyzed using Fourier optics, and reveals that in addition to the main, expected spots, secondary spots with smaller intensities also appeared as a result of diffraction by the small dimensions of the micro-lens and interference from the different micro-lenses. This result is confirmed by comparing with a irradiance pattern taken from an actual SHWS. The additional error in centroid estimation caused by these secondary spots is discussed and relationship to the parameters of the micro-lens of SHWS is analyzed.     

Correspondence Between Oscillations and Emitted Photon Closed-Orbits in Spontaneous Emission Rate of an Atom Near a Dielectric Slab

We study the oscillations in the spontaneous emission rate of an atom near a dielectric slab. The emission rate is calculated as a function of system size using quantum electrodynamics. It exhibits multi-periodic oscillations. Four frequencies of the oscillations are extracted by Fourier transforms. They agree with actions of photon closed-orbits going away and returning to the atom. These oscillations are explained as manifestations of quantum interference effects between the emitted photon wave near the atom and the returning photon waves travelling along various closed-orbits.     

荷移荧光光谱法测定加替沙星

研究了加替沙星(GFLX) 与电子受体四氯对苯醌(TCBQ)之间的荷移反应,建立了测定加替沙星的新方法。实验结果表明,在甲醇-水介质中于45 ℃水浴恒温20 min,GFLX与TCBQ可形成稳定的1∶1电荷转移络合物,其荧光发射强度较GFLX本身有显著的增强。在0.19～5.6 mg·L-1 浓度范围内,荧光强度与GFLX浓度呈良好的线性关系,检出限为0.005 6 mg·L-1。用于药物制剂中GFLX的含量测定,其回收率为101.1%～103.9%;标准偏差为1.0%～1.9%。同时建立了测定尿样中GFLX的荷移同步荧光光谱法,GFLX浓度在0.023～3.4 mg·L-1范围内与荧光强度呈良好的线性关系,检出限为0.003 4 mg·L-1。用本方法测定尿液中的GFLX,结果与文献值基本一致,回收率为93.9%～101.0%;标准偏差为1.0 %～1.7%。